This application is related to applicant's pending application Ser. No. 07/877,212, entitled "Cord Retraction Device", now U.S. Pat. No. 5,279,473.
Retraction devices for the taking up of slack in free-ended cords, chains and the like (all of which will be collectively referred to herein as "cord") exist for many applications. However, a device capable of use in association with a vertical window blind (i.e., a blind having vertically-oriented slats depending from a head unit) must be capable of retracting a cord loop, since the blind opening cord (as opposed to the slat-rotating means) of a vertical blind typically comprises a long continuous loom, which may be cycled alternately in one direction or the other for the opening or closing of the blind. For safety and aesthetic reasons it is desirable to retract a portion of the cord loop. The device must be capable, in its unretracted position, of allowing the cord to freely pass through the device in order to allow the cord loop to cycle through the blind head. It is desirable to provide a device capable as well of retracting the free-ended cords found in venetian blinds. Further, i% is desirable to provide a device that is capable of easy engagement to a cord, for the convenience of the user.
While many retraction devices exist for the taking up of free-ended cords, these existing devices do not provide an adequate solution to the requirements of window blind cords. For example, the cord retraction device disclosed U.S. Pat. No. 4,271,893 (McClusky) comprises a typical arrangement of a spring-driven spool rotatably engaged within a housing; means are not provided to allow a cord loop to cycle through the device in the unretracted position.
The retraction device described and claimed in the applicant's pending U.S. application Ser. No. 07/877,212 provides a device comprising a rotatably-driven spool within a housing, wherein the spool is provided with attachment means adapted to alternately slidingly and fixedly engage a cord loop, wherein the cord is free to slide through the attachment means when the cord is in the unwound but is fixedly engaged to the spool when retracted. The device also serves as a conventional take-up device for use with the free-ended cords of a venetian blind.
It is desirable that any such device be simple and easy to use, in order to minimize manufacturing costs, provide ease of assembly and use, and be reliable and long lasting. Accordingly, it is desirable that the number and complexity of components of the device be reduced to a minimum. The present invention provides a simpler version of the device described in applicant's said prior invention.